TY - JOUR
T1 - Orientation Control of Solution-Processed Organic Semiconductor Crystals to Improve Out-of-Plane Charge Mobility
AU - Bai, Xiaoshen
AU - Zong, Kai
AU - Ly, Jack
AU - Mehta, Jeremy S.
AU - Hand, Megan
AU - Molnar, Kaitlyn
AU - Lee, Sangchul
AU - Kahr, Bart
AU - Mativetsky, Jeffrey M.
AU - Briseno, Alejandro
AU - Lee, Stephanie S.
N1 - Funding Information:
The authors are grateful for the assistance of Dr. Chunhua Hu at the Department of Chemistry of New York University with 2D XRD experiments and acknowledge support by the National Science Foundation under Award Number CRIF/ CHE-0840277 and by the NSF MRSEC Program under Award Number DMR-0820341. J.M.M. and J.S.M. acknowledge support from the National Science Foundation (CAREER award DMR-1555028) for the C-AFM measurements. Research was carried out in part at the Micro Device Laboratory and used microscopy resources within the Laboratory for Multiscale Imaging at Stevens Institute of Technology, and the authors thank Dr. Tsengming Chou for assistance. J.L. and A.B. acknowledge funding from the National Science Foundation (DMR-1508627).
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/9/12
Y1 - 2017/9/12
N2 - The crystallization of a series of triisopropylsilylethynyl (TIPS)-derivatized acene-based organic semiconductors drop cast from solution onto substrates was investigated as a function of the size of their conjugated cores. When drop cast onto a substrate, the molecules in TIPS-pentacene crystals adopt a "horizontal" orientation, with the long axis of the pentacene core parallel to the substrate surface. For crystals comprising molecules with dibenzopyrene, anthanthrene, and pyranthrene cores, two-dimensional X-ray diffraction patterns revealed the existence of a second population of crystals adopting a "vertical" molecular orientation with the long axis of the acene core perpendicular to the substrate surface. The ratio of the population of TIPS-pyranthrene crystals with molecules adopting horizontal versus vertical orientations was controlled by varying the surface energy of the underlying substrate. These crystals displayed orientation-dependent linear birefringence and linear dichroism, as observed by differential polarizing optical microscopy. Conductive atomic force microscopy (C-AFM) revealed a 42-fold improvement in out-of-plane hole mobility through crystals adopting the vertical molecular orientation compared to those adopting the horizontal molecular orientation.
AB - The crystallization of a series of triisopropylsilylethynyl (TIPS)-derivatized acene-based organic semiconductors drop cast from solution onto substrates was investigated as a function of the size of their conjugated cores. When drop cast onto a substrate, the molecules in TIPS-pentacene crystals adopt a "horizontal" orientation, with the long axis of the pentacene core parallel to the substrate surface. For crystals comprising molecules with dibenzopyrene, anthanthrene, and pyranthrene cores, two-dimensional X-ray diffraction patterns revealed the existence of a second population of crystals adopting a "vertical" molecular orientation with the long axis of the acene core perpendicular to the substrate surface. The ratio of the population of TIPS-pyranthrene crystals with molecules adopting horizontal versus vertical orientations was controlled by varying the surface energy of the underlying substrate. These crystals displayed orientation-dependent linear birefringence and linear dichroism, as observed by differential polarizing optical microscopy. Conductive atomic force microscopy (C-AFM) revealed a 42-fold improvement in out-of-plane hole mobility through crystals adopting the vertical molecular orientation compared to those adopting the horizontal molecular orientation.
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U2 - 10.1021/acs.chemmater.7b02771
DO - 10.1021/acs.chemmater.7b02771
M3 - Article
AN - SCOPUS:85029308227
SN - 0897-4756
VL - 29
SP - 7571
EP - 7578
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 17
ER -